Using a select query, if you
want to fetch data in the order of an attribute, the order by the
statement is necessary.
Let us retrieve the name,
author, publisher, published on, and price information from the book
table. The result is shown in the following table.
You can check that the tuples
are not sorted in order of any attribute. Thus, if you want to retrieve
the data in order of any attribute, you can use order by statement with
select queries. The following table shows results where data has been
retrieved in order of book name.
By default the sorting will be
performed in ascending order, if you want to sort them in reverse
(descending) order, you may use desc at the end, as order by name desc.
The result in order of price is
shown in the following table.
Now, we are preparing the table with more data to understand
order by on multiple attributes. After truncating the table the
following SQL queries are being executed to insert data.
insert into books values ('C Programming Language', 2,
'9780131103627', 'Brian W. Kernighan, Dennis M. Ritchie', 'Paperback',
'Prentice Hall', 'April 1988', 67.00);
insert into books values ('Java: A Beginners Guide', 7,
'9781259589317', 'Herbert Schildt', 'Paperback', 'McGraw-Hill
Education', 'October 2017', 40.00);
insert into books values ('Python Programming', 1,
'9781590282755', 'Zelle, John', 'Paperback', 'Franklin, Beedle &
Associates', 'April 2014', 70.00);
insert into books values ('Design and Analysis of Algorithm',
1, '9781976735974', 'BHUPENDRA SINGH MANDLOI', 'Paperback',
'Independently published', 'January 2018', 5.00);
insert into books values ('Introduction to Algorithms', 3,
'9780262033848', 'Thomas H. Cormen, Charles E. Leiserson, Ronald L.
Rivest, Clifford Stein', 'Hardcover', 'The MIT Press', 'July 2009',
99.00);
insert into books values ('Operating Systems', 2,
'9780985673529', 'Thomas Anderson, Michael Dahlin', 'Paperback',
'Recursive Books', 'August 2014', 72.00);
insert into books values ('C Programming Language', 2,
'9780131103627', 'Brian W. Kernighan, Dennis M. Ritchie', 'Paperback',
'McGraw-Hill Education', 'April 1988', 67.00);
insert into books values ('Java: A Beginners Guide', 7,
'9781259589317', 'Herbert Schildt', 'Paperback', 'McGraw-Hill
Education', 'October 2017', 40.00);
insert into books values ('Python Programming', 1,
'9781590282755', 'Zelle, John', 'Paperback', 'The MIT', 'April 2014',
70.00);
insert into books values ('Design and Analysis of Algorithm',
1, '9781976735974', 'BHUPENDRA SINGH MANDLOI', 'Paperback',
'McGraw-Hill Education', 'January 2018', 5.00);
insert into books values ('Introduction to Algorithms', 3,
'9780262033848', 'Thomas H. Cormen, Charles E. Leiserson, Ronald L.
Rivest, Clifford Stein', 'Hardcover', 'The MIT', 'July 2009', 99.00);
insert into books values ('Operating Systems', 2,
'9780985673529', 'Thomas Anderson, Michael Dahlin', 'Paperback',
'McGraw-Hill Education', 'August 2014', 72.00);
Now, the table is shown below.
The order by can be used for
multiple attributes. In that case, first, the tuples will be sorted
based on the first attribute followed by other attributes in sequential
order. In the following example, we have shown how multiple attributes
can be associated with the order by.






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